“We made use of the concept that white powders have a colour fingerprint that can be seen using a process known as spectrometry.

Scientists made use of a concept that the powders have a `fingerprint´ (Lauren Hurley/PA)

“The powders have different chemical bonds and this affects how they absorb light.

“By analysing the contrast between the infrared light we beam at the powders, compared to what colours come back, we can identify individual chemicals and compounds.

“This has an obvious application for narcotics detection.

“We know that there is an appetite for portable crime scene technology that can reduce the risks faced by personnel while providing accurate and instant results.

“The laser technology has recently been commercialised by Heriot-Watt spinout company Chromacity Ltd, so it’s now a short step to develop a directory of powder fingerprints that would allow users to quickly identify the powder that’s in front of them, without delay or danger.”

The team at the university were able to identify 11 white powder samples using their infrared laser system.

No samples or disturbance of the powders were required and they could be identified from up to one metre away.